Method for producing negative carbon fuel

ABSTRACT

A method and process is described for producing negative carbon fuel. In its broadest form, a carbon-containing input is converted to combustible fuels, refinery feedstock, or chemicals and a carbonaceous solid concurrently in separate and substantially uncontaminated form. In an embodiment of the invention, biomass is converted via discrete increasing temperatures under pressure to blendable combustible fuels and a carbonaceous solid. The carbonaceous solid may be reacted to synthesis gas, sold as charcoal product, carbon credits, used for carbon offsets, or sequestered.

REFERENCES TO RELATED APPLICATIONS

This application is a Continuation of U.S. patent application Ser. No.14/036,480 filed Sep. 25, 2013, which claims priority to U.S. patentapplication Ser. No. 13/189,709, filed on Jul. 25, 2011, issued as U.S.Pat. No. 8,568,493 on Oct. 29, 2013, which applications are incorporatedherein by reference in their entirety.

TECHNICAL FIELD

The present invention relates generally to biofuel and more particularlyto methods for producing negative carbon biofuel by concurrentproduction of biofuel and sequesterable biochar in unmixed form frombiomass.

DESCRIPTION OF THE RELATED ART

Negative carbon fuels are defined as fuels that are produced via aprocess that also sequesters some of the carbon contained in thecarbon-containing feedstock used to produce the fuel. A similar andrelated concept is that of carbon negative fuels, which refer to fuelswhose production removes more carbon dioxide from the atmosphere thancarbon dioxide emitted from combustion and carbon dioxide added fromprocesses used to make the fuels. Both are possible if some of thecarbon from a carbon-containing input (e.g. biomass) is removed to theground in more or less permanent form, while the remaining carbon fromthe input is converted to fuel. The production of negative carbon fuelsor carbon negative fuels is desirable because the biosphere is presentlyoverburdened by carbon emissions produced from fossil fuels. The burningof fuels presently contributes to an annual release of 4 billion metrictons of carbon dioxide into the atmosphere and the injection of 2billion metric tons of carbon dioxide into the world's oceans. It hasbeen well documented that these carbon emissions negatively impactliving organisms in the oceans as well as on land.

There is presently intense interest in producing biofuels from a widevariety of feedstocks, in order to provide suitable replacements forfossil fuels. In particular, it is desirable to combine biofuelproduction with carbon sequestration, yielding a negative carbon orcarbon negative product. The idea of carbon negative fuels has beenpreviously discussed. See, for example, J. A. Mathews, “Carbon-negativebiofuels”, in Energy Policy 36 (2008) pp. 940-945. Typical production ofbiofuels, however, utilizes pyrolysis processes which produce a resinousmixture of oil and carbon along with significant amounts of CO2. The gasstreams that are produced are contaminated with various agents, such assulfur. The carbon is also contaminated with tar products. It isdesirable to find a process which produces negative carbon or carbonnegative fuel in which the fuel and the carbon are produced as separateand uncontaminated products.

Approaches directed toward the production of carbon negative fuelsinclude those described in US Patent Publication 2010/0311157, whichteaches the production of biofuels from algae as feedstock. The processis claimed to be carbon negative due to the high absorption of CO₂ bythe algae. US Patent Publication 2010/0040510 discloses a multistagepressurized fluidized bed gasifier operating between 780° C. and 1100°C. that converts biomass to synthesis gas and biochar. The biochar issaid to be capable of being added to soil. The formation of methane,gasoline-like volatiles such as BTX (benzene, toluene, and xylene) andtar is explicitly avoided. The gasifier is said to possibly producecarbon negative fuel. US Patent Publication 2008/0317657 discloses asystem and method for sequestering carbon in the form of char created bygasifying biomass in an unspecified reactor vessel. A low heating valueproducer gas is a by-product of the process. US Patent Publication2004/0111968 discusses pyrolyzing biomass to produce char and pyrolysisgases which are steam reformed to hydrogen. The char is treated tobecome a carbon based fertilizer.

BRIEF SUMMARY OF EMBODIMENTS OF THE INVENTION

In its most general form, the present invention discloses a method formaking negative carbon fuel via the concurrent production of combustiblefuels (and chemicals) and carbon in unmixed form from acarbon-containing input. In an embodiment of this invention, thecarbon-containing input may include biomass. In another embodiment, theprocess may include a selective pyrolysis of biomass performed in anovel reactor using discrete increasing temperatures under pressure.This process is called biofractioning. The novel reactor has beendescribed in detail in co-owned U.S. patent application Ser. 13/103,905,titled “Method for Biomass Fractioning by Enhancing ThermalConductivity” and co-owned U.S. patent application Ser. 13/019,236,titled “System and Method for Biomass Fractioning,” the contents ofwhich are incorporated herein by reference in their entireties.

The carbon produced from this biofractioning process is sequestered.Using this process the resulting fuel is negative carbon. The fuel andthe carbon arise separately and substantially uncontaminated, avoidingthe resinous mixture of standard processes. In a still anotherembodiment, the biofractioning process produces carbon negative fuel.

One embodiment of the invention is directed toward a method for makingnegative carbon fuel, comprising: concurrently converting acarbon-containing input to: (a) combustible fuels, refinery feedstock orchemicals; and (b) sequesterable carbon; wherein the combustible fuels,refinery feedstock or chemicals arise, in substantially separate anduncontaminated form from the sequesterable carbon. In some cases, thecarbon-containing input may comprise biomass. The step of converting thecarbon-containing input may comprise, e.g., subjecting biomass to rampsof temperatures under pressure, wherein the pressure increases thethermal conductivity of the partially carbonized biomass. In oneimplementation, subjecting biomass to ramps of temperatures underpressure is performed using mobile equipment. The method may furthercomprise choosing a biomass conversion route based on a composition ofthe biomass and/or dispensing the biomass as thin sheets.

In some embodiments, a ratio of sequesterable carbon to combustible fuelis controlled via selection of biomass feedstock or by selection oftemperature ramp profile and pressure. By way of example, thesequesterable carbon may be sequestered by use as a soil amendment, byunderground storage as coal, or by addition to soil containing compostmaterial. The sequesterable carbon may be used for carbon offsets and/orcarbon credits. According to one implementation, at least some of thesequesterable carbon is reacted with oxygen, carbon dioxide, methane orsteam to generate synthesis gas. The synthesis gas may be converted tocombustible fuels, refinery stock or chemicals. In some cases, at leastone of the combustible fuels, refinery stock or chemicals is certifiedas carbon negative.

The above method may further comprise blending the combustible stocks,refinery stock, or chemicals with one or more of: gasoline, diesel, jetfuel, kerosene, light naphtha, heavy naphtha, light cycle oil, and heavycycle oil. Additionally, the method may further comprise blending thecombustible stocks, refinery stock, or chemicals with one or more of:methanol, ethanol, propanol, isopropyl alcohol, n-butanol, t-butanol,pentanol, hexanol, butanediol, dimethyl ether, methyl tert-butyl ether(MTBE), tertiary amyl methyl ether (TAME), tertiary hexyl methyl ether(THEME), ethyl tertiary butyl ether (ETBE), tertiary amyl ethyl ether(TAEE), and diisopropyl ether (DIPE). In further embodiments, the methodmay also comprise blending the combustible stocks, refinery stock, orchemicals with one or more of: detergent, combustion improver, cetaneimprover, emulsifier, antioxidant, antifoam agent, corrosion inhibitor,wax crystal modifier, icing inhibitor, lubricity agent and distillateflow improver.

Another embodiment of the invention is directed toward an unleaded fuelblend produced according to the above method and suitable for combustionin an automobile or aviation engine, the fuel blend comprising: 0.5% ormore of combustible fuel or refinery feedstock; and 99.5% or less of oneor more of: gasoline, diesel, jet fuel, kerosene, light naphtha, heavynaphtha, light cycle oil, and heavy cycle oil.

Other features and aspects of the invention will become apparent fromthe following detailed description, taken in conjunction with theaccompanying drawings, which illustrate, by way of example, the featuresin accordance with embodiments of the invention. The summary is notintended to limit the scope of the invention, which is defined solely bythe claims attached hereto.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention, in accordance with one or more variousembodiments, is described in detail with reference to the followingfigures. The drawings are provided for purposes of illustration only andmerely depict typical or example embodiments of the invention. Thesedrawings are provided to facilitate the reader's understanding of theinvention and shall not be considered limiting of the breadth, scope, orapplicability of the invention. It should be noted that for clarity andease of illustration these drawings are not necessarily made to scale.

FIG. 1 is a flow diagram illustrating a method of making negative carbonfuel in accordance with an embodiment of the invention.

FIG. 2 is a flow diagram illustrating a method in which biomass is thecarbon-containing input in accordance with an embodiment of theinvention.

FIG. 3 is a flow diagram illustrating a method in which biomass is thecarbon-containing input and biofractionation is the process whichproduces negative carbon fuel.

FIG. 4 is a flow diagram illustrating a method for biomass treated witha bio-fractionation process to produce negative carbon fuel inaccordance with an embodiment of the invention.

FIG. 5 is a flow diagram illustrating various paths for the productionof negative carbon fuel.

FIG. 6 is a block diagram illustrating an embodiment for producingnegative carbon fuel.

FIG. 7 is a flow diagram illustrating the basic operational principlesbehind the conversion of biomass into BMF char, in accordance with anembodiment of the invention.

FIG. 8 is a diagram illustrating an example of applied pressure andcorresponding biomass pressure and temperature within the reactionchamber, as well as anvil position during this time interval, inaccordance with an embodiment of the invention.

FIG. 9 is a diagram illustrating the conversion of fuels from variousfeedstocks in accordance with an embodiment of the invention.

FIG. 10a is a diagram illustrating a carbon closed loop approach of thepresent invention in which biochar is sequestered as soil enhancer; FIG.10b is a flow diagram illustrating a process for rendering biocharsuitable as a soil enhancer.

FIG. 11 is a flow diagram illustrating a process for determining whethera process produces negative carbon fuel, in accordance with anembodiment of the invention.

FIG. 12 is a flow diagram illustrating possible carbon pathways inaccordance with an embodiment of the invention.

FIG. 13 is a flow diagram illustrating an embodiment of the presentinvention in which some carbon is sequestered and some carbon isconverted to syngas prior to conversion to fuel.

FIG. 14 is an illustration of an embodiment of a system capable ofproducing negative carbon fuel.

FIG. 15 is an illustration of an embodiment of a system capable ofexecuting various methods of the present invention using mobileequipment.

The figures are not intended to be exhaustive or to limit the inventionto the precise form disclosed. It should be understood that theinvention can be practiced with modification and alteration, and thatthe invention be limited only by the claims and the equivalents thereof.

DETAILED DESCRIPTION OF THE EMBODIMENTS OF THE INVENTION

Embodiments of the invention are directed toward methods for producingnegative carbon biofuel by concurrent production of biofuel andsequesterable biochar in unmixed form from biomass.

FIG. 1 is a flow diagram illustrating a method of making negative carbonfuel in accordance with an embodiment of the invention. Specifically, acarbon-containing input 200 is processed in process 250 to produceconcurrently combustible fuels and chemicals 290 and sequesterablecarbon 270 in a substantially uncontaminated and separate form.Combustible fuels and chemicals 290 can be negative carbon, whilecarbon-containing input 200 can include, but is not limited to, biomass,biomass-containing material, hydrocarbons, oxygenates such as alcohols,aldehydes, ketones and ethers. Process 250 refers to any sequence ofsteps that convert the carbon-containing input 200 into outputs 290 and270 as separate entities in a substantially uncontaminated form. Theseprocesses can include, but are not limited to, a biofractionationprocess which thermo-chemically converts the input at increasingtemperatures under pressure. Sequesterable carbon 270 refers to anycarbon that is stored for long periods of time, including carbon that isstored underground or used as a soil amendment. Combustible fuels andchemicals 290 can include, but are not limited to, gasoline,gasoline-components, jet fuel, diesel, naphtha, oxygenate fuels such asmethanol and dimethyl ether, hydrogen, methane, light gas oil, andvacuum gas oil. The process for determining whether output 290 isnegative carbon is discussed hereinbelow with respect to FIG. 11.

FIG. 2 is a flow diagram illustrating an embodiment of the invention inwhich the carbon-containing input comprises biomass. Biomass 300 is fedas input into process 350, which concurrently outputs combustible fueland chemicals 390 and sequesterable carbon 370 as substantiallyuncontaminated and separate entities.

As used herein, the term ‘biomass’ includes any material derived orreadily obtained from plant sources. Such material can include withoutlimitation: (i) plant products such as bark, leaves, tree branches, treestumps, hardwood chips, softwood chips, grape pumice, sugarcane bagasse,switchgrass; and (ii) pellet material such as grass, wood and haypellets, crop products such as corn, wheat and kenaf. This term may alsoinclude seeds such as vegetable seeds, sunflower seeds, fruit seeds, andlegume seeds. The term ‘biomass’ can also include: (i) waste productsincluding animal manure such as poultry derived waste; (ii) commercialor recycled material including plastic, paper, paper pulp, cardboard,sawdust, timber residue, wood shavings and cloth; (iii) municipal wasteincluding sewage waste; (iv) agricultural waste such as coconut shells,pecan shells, almond shells, coffee grounds; and (v) agricultural feedproducts such as rice straw, wheat straw, rice hulls, corn stover, cornstraw, and corn cobs.

FIG. 3 is a flow diagram illustrating a method in which biomass is thecarbon-containing input and biofractionation is the process whichproduces negative carbon fuel. This process subjects the biomass todecomposition using temperature ramps under pressure. It is described indetail in co-owned U.S. patent application Ser. Nos. 13/103,905 and13/019,236.

Referring now to FIG. 3, biomass 405 is inputted into biofractionationprocess 420 to concurrently produce combustible fuels and chemicals 500and sequesterable carbon 425. FIGS. 4 and 5 show additional embodimentsof the embodiment shown in FIG. 3, wherein biomass 405 is pretreated inoperation 410 prior to being subjected to the bio-fractioning process420. The conversion process produces sequesterable carbon 425 (sometimesreferred to herein as BMF char) and volatile gas streams 423.

With continued reference to FIGS. 4 and 5, the volatile gas streams 423are transformed to commercial grade fuels 495 via separation andblending processes 480 and 490, respectively, which can also producesaleable chemicals 481 and 491. An optional fuel conversion process 470converts the volatile gas streams to renewable fuel components 473. BMFchar 425 may partly be converted to synthesis gas via syngas productionstep 450. The synthesis gas can have numerous uses, including conversionto fuels and fuel precursors via process 460, and utilization in energyproduction or chemical production 455. Syngas production process 450 canreceive input from: (i) biochar processing 430, (ii) external sources ofhydrogen, carbon or oxygen 431, (iii) recycled carbon monoxide or carbondioxide from process 460, or (iv) recycled gases after the separationprocess 482.

In some embodiments, BMP char 425 may be sequestered in undergroundstorage product 434. BMP char may also be mixed with compost to yieldsequestered product 433. Direct utilization of the biochar as a soilamendment is also possible, since the residence time of biochar in soilis in the order of millennia. The latter has been determined from thepersistence of biochar as a soil enhancement agent in Amazonian soilterra preta. BMF char 425 may also be upgraded via different techniquesand sold as a soil fertilizer 439 to enhance soil growth. In furtherembodiments, BMP char 425 may optionally be processed prior to beingsold directly for various end uses such as activated charcoal, gaspurifier, coal purifier and water purifier. The commercial gradenegative carbon fuels 495 arise from the concurrent production ofbiofractionation-derived renewable fuels and sequesterable biochar.

FIG. 6 is a block diagram illustrating an embodiment for producingnegative carbon fuel. In this embodiment, biomass as carbon-input isbiofractionated into volatile components which arise from conversion oflipids, hemicellulose, and lignins within the biomass. The volatilecomponents may be catalytically converted to fuels and saleablechemicals. The carbon (as biochar) that is produced may be used asactivated carbon, or sequestered via use as a soil enhancer, undergroundstorage, or mixture with compost. The basic steps involved in thebiofractionation process will now be described in further detail.

Biomass Pretreatment

Referring again to FIG. 4, operation 410 involves the pretreatment ofthe biomass prior to being subjected to bio-fractioning process 420. Thepurpose of the pretreatment is to facilitate the subsequentbio-fractioning process 420, which involves a stepwise decomposition ofbiomass at increasing temperatures under pressure. This process isfacilitated if the biomass is ground and dispensed onto a chamber as athin sheet. The biomass may be ground by a variety of equipmentincluding, but not limited to, equipment for making mulch, chips,pellets, or sawdust. Ground particle size may range from 0.001 inch to 1inch in diameter, limited by processing equipment size and thermaltransfer rates.

Embodiments of the invention feature dispensation onto a biomass chamberthat is much wider and longer than it is thick. In some eases, biomassis dispensed into thin sheets whose total thickness is 1 to 30 times thebiomass particle size. In some cases, a preferred thickness for thechamber for uncompressed biomass (which is ground or chopped to 1/8″ orsmaller) is approximately 3/4″ in thickness. As the biomass is heatedand further pulverized (as discussed below), the emerging BMF charquickly condenses to a layer about 1/10″ thick. This aspect ratioensures mild pyrolyzing conditions that allow the collection of usefulchemical compounds known as bio-intermediary compounds as well as theproduction of BMF char. A person of skill in the art will appreciatethat these biomass chambers can be sized in width and length along withthe diameter of their corresponding drive disc to any such size asappropriate for the desired throughput for the biomass fractionator,without departing from the scope if the invention.

Dispensation as thin sheets assures an environment similar to laboratoryscale mild pyrolysis conditions. In practice the environment is scalablein that it can be expanded in two dimensions to any practical workingthroughput while retaining a constant thickness for heat treatment ofincoming materials. The biomass may be dispensed in pre-dried form, orit may be dried after dispensation. Biomass may be loaded piecemeal ontoa plurality of movable biomass reaction chambers which are movable usingconventional drive mechanisms such as gear drives, chain drives,ratcheting sprockets, etc. In addition to linear displacements, thereaction chambers may also be arranged on a disc that rotatescontinuously or in a stepwise fashion.

Biomass Biofractioning

In some embodiments, the dispensed biomass is subjected to a novelbiofractioning process 420 described in detail in co-owned U.S. patentapplication Ser. Nos. 13/103,905 and 13/019,236. This process subjectsthe biomass to decomposition that produces volatile gas streams 423using discrete temperature increments under pressure. The pressureserves to increase the thermal conductivity of partially carbonizedbiomass and accelerates the decomposition.

FIG. 7 is a flow diagram illustrating the basic operational principlesbehind the conversion of biomass into BMF char, in accordance with anembodiment of the invention. In particular, FIG. 7 depicts the timesequence of the processes in the embodiments shown in FIGS. 4 and 5.Referring to FIGS. 5 and 7, biomass 51 is pretreated in process 410 andthen subjected to a series of temperature ramp profiles (ΔTn) andpressure shock profiles (ΔPn), where n is an integer greater than 1 thatdescribes the stages in the step-wise decomposition of the biomass 51.In particular, the biomass 51 is subjected first to a heating profileΔT1, typically a linear temperature ramp, by a heating agent such as ametal anvil at processing station 68. Typically, the purpose of thefirst ΔT1 profile is to dewater the biomass, producing processing water421. Subsequent ΔTn profiles end at progressively higher temperaturesand serve the purpose of outgassing and thermo-chemically convertingsolid biomass to volatile bio-compounds. These useful bio-compoundsemerge at progressively higher devolatilization temperatures. In orderto accomplish this devolatilization in a selective manner, thetemperature treatment is accompanied by a pressure treatment. In theembodiment of FIG. 7, this is achieved using compacting station 69(e.g., a series of anvils) for subjecting the biomass to accompanyingpressure profiles ΔPn comprising a sequence of pressure shocks thatexploit the inherent compressional features of carbon.

In some embodiments, the temperature profiles are linear ramps rangingfrom 0.001° C./sec to 1000° C./sec, and preferably from 1° C./sec to100° C./sec. Processing heating station 68 may be heated by electricalheating elements, direct flame combustion, or by directed jets of heatedworking gas or supercritical fluid. For a given n, the healing profileand the pressure compaction profile may be linked via a feedback loop,or may be applied by the same agent simultaneously. Compacting station69 may be controlled by electrically driven devices, air compresseddevices, or any other form of energy that serves to impact load thebiomass. A given volatile component or set of volatile components 423 ofthe decomposed biomass are collected after each application of atemperature ramp and pressure profile. After these processing steps, BMPchar 425 emerges ready for the sequestration process 80.

The selective pyrolysis of the biomass arises out of the interplaybetween the applied pressure pulses, applied temperature and resultantpressures and temperatures experienced by the biomass. The process isillustrated diagrammatically in FIG. 8, which shows applied pressure,biomass temperature, biomass pressure and anvil position as a functionof time. It is understood that a wide variety of different types ofpressure pulses may be applied, and that the entire illustration is anexpository device. In FIG. 8, pressure shocks applied via compactingstation 69 (in FIG. 7) are shown as a series of triangular pressurepulses with an unspecified rest time. The process begins by utilizingthe thermal conductivity of water. The biomass is first subjected to atemperature ramp sufficient to cause the biomass to release water. Thereleased heated water vapor is then subjected to a pressure shock, whichcompresses the steam, thus accelerating the biomass decomposition. Insome embodiments of the invention, the steam attains a supercriticalstate. In other embodiments, the steam does not attain a supercriticalstate.

With continued reference to FIG. 8, the pressure shock also aids incollapsing the biomass. A short time after peak pressure is applied, theanvil is pushed back by the pressure of extracted volatile compounds.When the volatile compounds are removed along with the steam, pressurewithin the biomass is decreased suddenly. Biomass temperature rapidlyreturns to base levels, and the anvil returns to its un-extended baseposition. After the water has been removed entirely from the biomass,the applied temperature causes hot localized areas within the biomassthat initiate carbon formation. Compressive impacts on the newly formedcarbon serve in turn to increase the thermal conductivity of the carbon.The increased thermal conductivity serves to efficiently transmit heatenergy needed to break down the biomass to the next stage in itsdecomposition. Furthermore, because carbon exhibits compressionalmemory, compressive impacts are sufficient to exert this effect onthermal conductivity.

The compressional memory of carbon has been indirectly demonstrated instudies of commercial carbon resistors as low pressure gauges. SeeRosenberg, Z. et al International Journal of Impact Engineering 34(2007) 732-742. In these studies, metal discs were launched from a gasgun at high velocity such that they impacted an epoxy or Plexiglastarget in which a carbon resistor was embedded. Resistance changes weremeasured as a function of time after impact. It was noted that theresistance decreased rather rapidly in less than a microsecond, andstayed low for several microseconds, in some cases over 10 microseconds,until it began to increase gradually to pre-impact levels. Thisevidences a memory effect or a slow relaxation after the impact. Becauseelectrical resistance and thermal conductivity are inversely correlatedfor carbon as for metals (See, for example, Buerschaper, R. A. inJournal of Applied Physics 15 (1944) 452-454 and Encyclopedia ofChemical Technology, 5th edition), these studies reveal a compressionmemory on the part of the carbon. This compression memory is at leastpartly utilized in various embodiments of the invention.

Embodiments of the invention also utilize the increase in thermalconductivity as carbon is compressed. The change in electricalresistance with pressure in carbon microphones is a well-known effect,used by carbon telephones and carbon amplifiers. U.S. Pat. No. 203,216,U.S. Pat. No. 2,222,390 and U.S. Pat. No. 474,230 to Thomas Edison,describe apparatus that transform sound compressions (vibrations) tochanges in electrical resistance of carbon granules. Carbon is even moresensitive than most metals in its inverse relationship betweenelectrical resistance and thermal conductivity.

Below are data indicating the thermal conductivity of various substances(CRC Handbook of Chemistry and Physics, 87th edition) in comparison tothe measured thermal conductivity of BMF char:

TABLE 1 Select Thermal Conductivities in W/(m · K) Material ThermalConductivity Copper 390 Stainless Steel 20 Water 0.6 Dry Wood 0.3 Fuels0.1 to 0.2 Carrier Gases (H₂, N₂, etc.) 0.01 to 0.02 Carbon Char 0.01 to0.05 BMF char 1 to 5

As the thermal conductivity of the formed carbon within the biomassincreases due to pressure shocks, it becomes consequently easier toattain mild pyrolysis conditions within the biomass. As highertemperatures are reached, the fact that carbon is a better heat transferagent than water enables higher boiling compounds to become volatile.Pressure shocks serve to compress these higher boiling compounds andcontribute to fracturing cell walls within the biomass. The process isillustrated by FIG. 8, which shows anvil extension at peak pressuregetting longer with subsequent pulse application, thus indicatingsuccessive biomass pulverization in conjunction with release of usefulhigher boiling compounds.

A variety of pressure profiles ΔPn are effective in increasing thecarbon thermal conductivity. The magnitude of the pressure can vary from0.2 MPa to 10 GPa and may be applied via a number of differenttechnologies, including air driven pistons, hydraulically drivenpistons, and explosive driven devices. The duration of the pressureapplication can vary from 1 microsecond to 1 week. It is understood thatpressure pulses of different magnitudes and different time durations maybe admixed to yield optimum results.

The efficient heal energy transfer executed by embodiments of thepresent invention can be enhanced by the addition of supercriticalfluids in the reaction chamber. It is known that supercritical fluidscan improve heat transfer as well as accelerate reaction rates. Certainembodiments can operate with supercritical carbon dioxide, supercriticalwater, supercritical methane, supercritical methanol, or mixtures of theabove. It is possible that supercritical conditions are createdinternally with some pressure and temperature profiles.

A system capable of embodying the methods of the present invention isdescribed in co-owned, co-pending U.S. Patent Application No.2010/0180805 entitled “System and Method for Biomass Fractioning,” thecontent of which is incorporated herein by reference in its entirety.This system comprises a biomass load and dump station, a heatedpulverizing processing station for compressing the biomass, a biochardumping station for removing residual biochar, and a plurality ofbiomass reaction compartments able to carry the biomass from station tostation.

Fuel Conversion

Referring to FIG. 5, the volatile gas streams are optionally transformedto fuel compounds 473 via catalyst conversion process 470. These fuelcompounds are typically termed renewable fuels and can be applied to anycombustible fuel, such as gasoline, diesel, jet fuel and other fuelblend stocks such as BTX, derived from biomass and useful fortransportation or other purposes. Various catalyst systems may beemployed to effect this conversion depending on the nature of thevolatile gas streams and desired fuel component. In some embodiments, asystem is used wherein only a minimum number of bonds are broken andmade, and consequently, the minimum amount of energy is spent breakingand making these bonds.

A system and method rendering the catalytic conversion process moreefficient by using multiple programmable catalytic processing stationshas been described in co-owned U.S. patent application Ser. No.13/071,016 entitled “Method for Making Renewable Fuels” and co-ownedU.S. patent application Ser. No. 13/071,038 entitled “System for MakingRenewable Fuels.” These patents describe a programmable system forrouting biomass decomposition products through processing stations and aseries of catalysts. There are three basic routing schemes in thisprogrammable system, including: a) routing based on knowledge of theinitial composition of the biomass, b) routing based on knowledge of thetemperature of biomass component devolatilization, and c) routing basedon knowledge of product yield.

FIG. 9 shows an embodiment of high-yield fuel conversion using knowledgeof the initial composition of the biomass. Three different types ofbiomass feedstocks are shown as inputs to three processing stations,each being subjected to a particular array of catalytic columns foroptimal product yield. In general, the biomass feedstocks in variousstations can come from a single biomass input such that the feedstocksare subsequently processed using the three stations. Other embodimentsfeature multiple independent biomass inputs. While the number ofprocessing stations can vary, the same catalytic columns are used toconvert the volatile gases to renewable fuels. The order in which thecatalytic columns are selected can vary. In the illustrated embodiment,a hemicellulose-rich biomass is subjected to an aromatization catalystand gas-upgrading catalyst, while a lipid-rich biomass and a lignin-richbiomass are subjected to an additional dehydration catalyst, but atdifferent temperatures. The aromatization catalyst can be comprised ofMFI type zeolites and metal modified MFI type zeolites, where the metalis selected from the group consisting of: Group VIB metals, Group VIIBmetals, Group VIII metals, Group IB metals, Group IIB metals, Ga, In,and all combinations thereof. The gas-upgrading catalyst can becomprised of metal modified MFI type zeolites, where the metal isselected from the group consisting of: Ga, Zn, In, Mo, W, Cr, Pt, Pd,Rh, Ru, Au, Ir, and combinations thereof. The dehydration catalyst canbe any acid catalyst, such as heterogeneous solid acid catalysts.

Volatile components can be recirculated to at least one of thefollowing: a) one or more processing stations b) the dehydrationcatalyst, c) the aromatization catalyst or d) the gas-upgrading catalystin order to create fuels.

Separation and Blending

As depicted in FIG. 4, volatile gas streams are passed through aseparation process 480 after emerging directly from the biofractionationprocess 420 or catalytic conversion process 470. The separation process480 may include condensation of the gas streams and removal of water,carbon monoxide, carbon dioxide, methane and light gases 483 typicallycomprising C2-C5 compounds. Additional steps may be added which separatedifferent streams based on chemical or physical characteristics of theexiting streams. Saleable chemicals and light gases 481 may result fromthis process. The separation process may also be applied to liquid fuelsobtained after condensation. Separation in this case is based on liquidphysical characteristics, such as density, vapor pressure, or viscosity.The resulting renewable fuels 465 can be optionally blended in process490 with renewable fuels from other processes such as fermentation, orwith other fuels derived from fossil fuels, to produce suitablecommercial fuels 495 for different markets.

The co-blending fuels can include, but are not limited to, gasoline,diesel, jet fuel, methanol, ethanol, propanol, butanol, butanediol,isobutanol, and vegetable oil. A co-blending fuel can also include anyproducts from a fluidized catalytic cracking process, such as lightnaphtha, heavy naphtha, light cycle oil, heavy cycle oil, and kerosene.In some embodiments, additives may be added, to the fuel or fuel blends.Such additives may include without limitation: detergents, combustionimprovers, cetane improvers, emulsifiers, antioxidants, antifoam agents,corrosion inhibitors, wax crystal modifiers, distillate flow improvers,lubricity agents, icing inhibitors and antistatic agents.

Biochar Processing and Sequestration

After formation, BMF char 425 can be sold for numerous uses involvinglow surface and high surface area carbon, such as activated charcoal,gas purifier, coal purifier, water filter and water purifier. The BMFchar 425 may be optionally treated in process 430 prior to being sold.The latter process may entail increasing the biochar surface area via anumber of different reactions including those described herein. The BMFchar may also be sequestered as discussed in the following two sections.

Carbon Sequestration Approaches

With further reference to FIG. 5, the BMF char 425 obtained from thebiomass biofractionation step 420 can be sequestered in three ways,including (i) storage in underground storage formations as sequesteredcompound 434, (ii) sequestered by simple mixing with compost to yieldproduct 433, or (iii) used as a soil additive 439. In all cases, theresidence time for the sequestration is expected to be at leastthousands of years. In one embodiment for underground storage, describedin co-owned US Patent Application 2010/0257775, titled “System andMethod for Atmospheric Carbon Sequestration,” carbon is densified intoanthracite-style carbon aggregations (coal) and stored in geologicallystable underground deposits. The content of this application isincorporated herein by reference in its entirety. In another embodiment,carbon dioxide can be sequestered by injection in supercritical forminto oil wells. One embodiment for carbon sequestration using a soiladdition entails simple dispersal of BMF char onto soil. Sequesteredproduct 433 can produce considerable amounts of methane and carbondioxide due to the decomposition of the compost material. Sequesteredproducts 434, 439 do not produce methane or carbon dioxide, whereassequestered product 439 can be used to enhance soil growth.

Carbon Sequestration as Soil Amendment

In some embodiments, the sequestered carbon produced from fuelproduction can be employed to increase soil productivity in order tocounteract the ultimate burning of the fuel. FIG. 10a is a diagramillustrating a carbon closed loop approach of the present invention inwhich biochar is sequestered as soil enhancer. Specifically, FIG. 10adepicts the production of negative carbon fuel and subsequent biocharfor soil enhancement using corn cobs and corn stalks as the biomasssource. The closed loop nature for carbon dioxide utilization isdemonstrated in this figure in accordance with an embodiment of theinvention. Another embodiment relies on removing detrimental featuresinherent in biochars after formation, and in rendering the biochar poreshydrophilic in order to transform the biochar into a hospitableenvironment for microorganisms. The steps of this process are shown inFIG. 10b and will now be described.

Removal Of Hydrocarbons

Typical charcoal contains a variety of hydrocarbons in various stages ofdecomposition, depending on the last temperature to which the charcoalwas subjected. During early stages of heating, wood releases water vaporas it absorbs heat. Wood decomposition starts above 110° C., yieldingprimarily CO, CO2, acetic acid, methanol and traces of other components.Exothermic decomposition starts at around 280° C. and tar starts toform. Just above 400° C., the wood has been essentially converted intocharcoal, but this charcoal still contains about 1/3 of its weight intar material. Further heating is needed to drive off the tar. Because ofthe highly porous nature of wood, it is difficult to remove tar unlesssufficiently high temperatures are reached beyond the equilibriumdecomposition temperature of tar components. If present, small amountsof hydrophobic hydrocarbons, such as polyaromatic hydrocarbons (PAHs),within the char can inhibit colonization of the BMF char bymicroorganisms.

FIG. 10b is a flow diagram illustrating a process for rendering biocharsuitable as a soil enhancer. In particular, step 600 entails creatingBMF char using a biomass fractionator. In order to render the BMF charhospitable for subsequent microorganism invasion, step 610 involvesremoving the hydrophobic hydrocarbons. In many cases, temperatures above700° C. are required to remove the hydrophobic hydrocarbons from the BMFchar walls. The hydrocarbon removal step may be combined with anactivation step, which increases the char surface area, the activationstep may includes reactions of the biochar with steam, water or oxygen.

Removal of Adsorbed Gases from Char Pores

The next step in the rendering the BMF char more hydrophilic involvesprocess 620, which removes adsorbed gases within the BMF char pores toallow water infiltration. In some cases, the BMF char can be a highsurface area compound (typically in excess of 300 m2/g in activatedform) that contains significant amounts of adsorbed gas within itspores. Because the adsorbed gas has high adhesion to the pore surfaces,it is preferably removed. A simple method for removal of adsorbed air isto immerse the BMF char in boiling water. For short periods of time(e.g., several hours), it has been found that water uptake issubstantially insensitive to surface area, averaging around 50% uptakefor samples varying from 20 m2/g to 500 m2/g.

During or after the wetting step, optional soluble nutrients 437 may beintroduced as part of process 630. The nutrients enter a high surfacearea environment and can exchange adsorbed gases to some degree.Nutrients can include macronutrients containing nitrogen, phosphorus,potassium, calcium, magnesium, and sulfur as wells as micronutrientscontaining molybdenum, zinc, boron, cobalt, copper, iron, manganese andchloride. The high surface area BMP char affords plants more effectiveaccess to these nutrients. Additionally, the BMP char retains thesenutrients at times when rainfall tends to wash them off from the soil inthe absence of BMP char. Besides water infiltration, other methodsinclude ultrasonic, vacuum and impact removal of air.

Addition of Beneficial Microorganisms

With continued reference to FIG. 10 b, step 640 involves adding acompost agent. Once wetted, the BMP char is ready to accept beneficialmicroorganisms. These microorganisms may comprise fungi, archaea andbacteria that supply nutrients to plants symbiotically. Themicroorganisms may be introduced in a number of different ways,including mixing the BMF char with compost and water, adding compost teato the BMF char, blending the latter with compost, or blending the BMFchar with potting soil. Process 640 may encompass any or all of thesesteps. Some embodiments feature the use of a compost tea includingcommercial sources of compost tea such as Bu's Brew Biodynamic Tea®(Malibu Compost Inc, Santa Monica, Calif.), Nature's Solution CompostTea® (Nature's Technologies International LLC, Novato, Calif.) orMycoGrow® (Fungi Perfecti, Inc., Olympia, Wash.). The compost tea may beagitated to maintain an optimum oxygen concentration for microorganismsto thrive. Electric bubbling aerators, porous stones, or manual stirringare suitable methods to maintain sufficient aeration. Differentcompositions of fungi, archaea and bacteria may be used, depending ontarget soil.

Some embodiments may entail the use of beneficial fungi includingmembers of the arbuscular mycorrhizal fungi, which express theglycoprotein glomalin on their hyphae and spores. These fungi aremembers of the phyla Glomeromycota, which helps bind soil particlestogether and is responsible for good soil tilth. When introduced intoBMF char, the fungi expresses glomalin within the char pores and aids inmaintaining good soil structure by binding the biochar to soilparticles. Additionally, the root structure provided by the hyphaeallows nutrients to penetrate in and out of the high surface areaenvironment provided by the biochar.

Adjustment of Soil pH

It has been long been recognized that soil pH is an important variablein maintaining soil health and productivity. Soil pH tends to modify thebioavailability of plant nutrients. Some soils are inherently acidic orbasic in nature and a soil amendment should consider its effect on soilacidity. Biochar can differ in its effect on soil pH depending on thebiomass source of the biochar. Upon decomposition, corn cobs leave, forexample, significant amounts of K₂O in the biochar residue, and thiscompound tends to render the biochar basic. Addition of this basicbiochar to a soil that is already basic may be detrimental to the soil,pH management has been practiced inadvertently by Amazon Indians increating terra preta soils. Other materials are always present withcharcoal in terra preta soils, such as bones, fired clay bits and woodash. These materials buffer the acidic Latrelite soils. The bones andwood ash balance the pH of the acidic clay soils.

With further reference to FIG. 10b , step 650 involves adjusting soilpH. In some embodiments, soil pH can be shifted by adding pH adjustingcompounds directly to the soil alter BMF char addition. In otherembodiments, additives can be added to the BMF char that can shift theBMF char pH. In further embodiments, BMF char can be added directly tothe soil and left to self-neutralize for extended periods of time.

The first approach utilizes well known pH adjustment reactants appliedto soil. Neutralization compounds useful for acidic biochar can includeanions selected from the group of bicarbonates, carbonates, hydroxides,amines, nitrates, halides, sulfonates, phosphates, and carboxylates.These groups may comprise one or more functional groups within apolymer. This approach may also include oxides such as calcium oxide andmagnesium oxide, which upon exposure to air produce basic compounds.Neutralization compounds useful for basic biochar can include inorganicacids such as HCl, H₃PO₄, and H₂SO₄, and organic acids such as humic,vanillic and ferulic acids. A dispersant may be optionally used.

In the second approach, any of the compounds listed in the firstapproach may be applied directly to the BMF char. Additionally, BMF charmay be made less alkaline by impregnating it with bacterial compost tea(vide infra) containing acidic ingredients such as molasses, plantjuice, or algal extractives. The biochar may be made acidic by additionof inorganic acids such as HCl and H₂SO₄, and organic acids such ashumic, vanillic and ferulic acids. The biochar may be made more alkalineby addition of alkaline agents such as lime, bones, potassium carbonateor potassium hydroxide. Buffering agents may also be added. The thirdapproach requires long-term exposure to the atmosphere to neutralize thepH via carbonic acid formation.

Mixing Soil and Biochar

Step 660 in the method of FIG. 10b comprises mixing BMF char into soil.In particular, a wide variety of different techniques exist for applyingthe BMF char to soil. The incorporation of BMF char into soil may beaccomplished via BMF char integration into traditional farm machinery,such as the use of manure or lime spreaders in conjunction with plowingmethods utilizing rotary hoes, disc harrows, chisels, etc. Bandingmethods which allow BMF char use without significantly disturbing theunderlying soil may also be used. The BMF char may be added in solidform along with manure, compost, lime or mixed with water or liquidmanure and applied as a slurry. It may also be mixed with topsoil orapplied directly to an area where tree roots will extend.

Sequestration and Carbon Credits and Offsets

The simultaneous production of sequesterable carbon and renewable fuelsallows for negative carbon fuel production and for obtaining carboncredits and carbon offsets. Present venues for certifying carbon creditsunder regulatory regimes include, but are not limited to, the EuropeanUnion Emissions Trading Scheme, the United Nations Framework Conventionon Climate Change, and the Regional Greenhouse Gas Initiative of theNorth East United States. Organizations that certify voluntary emissionsreductions include, but are not limited to, the International StandardsOrganization (under standard 14064), the World Resources Institute(under GHG Corporate Accounting and Reporting Standard), theInternational Emissions Trading Association and the Climate Group (underVoluntary Carbon Standard), the World Wildlife Fund (under GoldStandard) and the Carbon Disclosure Project, the State of California(under the California Climate Action Registry), and the Western ClimateInitiative (under the WCI Cap-and-Trade Program).

FIG. 11 is a flow diagram illustrating a process for determining whethera process produces negative carbon fuel. The figure depicts a procedurefor an embodiment in which the carbon-containing input is comprised ofbiomass. Specifically, biomass is processed in process 700, whichconverts the input into combustible fuel and biochar as separate anduncontaminated products. Process 710 decides whether the process 700captures or sequesters carbon. If no carbon is captured or sequestered,the fuel is not negative carbon. If some carbon is captured, orsequestered, process 720 decides whether the carbon captured orsequestered is more than carbon obtained from any non-biomass carboninput. If the carbon captured or sequestered is more than the carboninput from a non-biomass source, then the produced fuels and productsfrom this process are negative carbon. If not, the fuel or products arenot negative carbon.

The procedure in FIG. 11 does not include carbon contributions to thebiomass feedstock aside from the carbon contained within the feedstock.However, other carbon contributions from non-biomass inputs to theprocess are counted. Such non-biomass inputs may include co-feedmaterials and carbon contributions from energy inputs which rely onfossil fuels. Once carbon negativity is established, the extent ofcarbon negativity can be set by process parameters (e.g., temperatureprofiles & pressure shock profiles) which yield a greater amount ofbiochar relative to combustible fuel. A variable N can be defined as:

N=(amount of carbon in biochar)/(amount of carbon combustible fuel)*100

The above equation quantifies the extent of carbon negativity. If theprocess produces an equal amount of biochar carbon to combustible fuelcarbon, N=100 and the fuel can be labeled as N100. This ratio can alsobe controlled by proper selection of the biomass feedstock.

FIG. 12 is a flow diagram illustrating possible carbon pathways from thepoint of view of carbon dioxide balance. Atmospheric carbon dioxide isthe source of carbon for the photosynthetic process that outputsbiomass. Energy is needed to collect and transport biomass, and theproduction of this energy leaves a carbon footprint. This carbonfootprint is not included in the procedure of FIG. 11. Other carbonfootprints are left during the production of energy to effect theconversion of biomass into fuel and sequesterable carbon, energy for theseparation and blending processes, and energy for biochar upgrading. Theconversion process itself may release carbon dioxide. External to theprocess, vehicles burning commercial fuel release carbon dioxide back tothe atmosphere. Sequestered carbon in soil may serve as a small sourceof carbon dioxide emission, depending on whether the carbon is mixedwith compost. In the production of combustible fuel and sequesterablecarbon as separate and uncontaminated products, some carbon dioxide isremoved from the atmosphere by sequestering carbon in soil.

Biochar Conversion to Synthesis Gas

Higher fuel yield (at a cost of carbon negativity) can be achieved byreacting some of the biochar to produce synthesis gas and converting thesynthesis gas to fuel. The method for this biochar conversion has beendisclosed in co-owned U.S. patent application Ser. No. 13/103,922entitled “Process for Biomass Conversion to Syngas,” the content ofwhich is incorporated herein by references in its entirety. The basicflow diagram for this conversion is shown in FIG. 13. After emergingfrom the biomass fractionator 420, the BMF char 425 is activated priorto use in step 53. Activation is a well-known procedure for treatingchars that increases char surface area and adsorptive capabilities.

BMF Char Reactions

BMF char can be reacted in char reactor 54 with one of CH₄, H₂O, CO₂ andO₂ as illustrated by the reactions:

C+CH₄->2H₂+2C ΔH°=75 kJ/mol  [1]

C+H₂O->CO+H₂ ΔH°=132 kJ/mol  [2]

C+CO₂->2CO ΔH°=72 kJ/mol  [3]

C+½O₂->CO ΔH°=−110 kJ/mol  [4]

Equation 1 may be more appropriately written as:

C_(BMF)+CH₄->2H₂+C_(BMF)+C_(methane)  [1a]

Thus the carbon in equations 2, 3, and 4 may represent either BMF carbonor carbon from methane, or both.

Any one of the above gaseous reactants with the BMF char may beintroduced in supercritical form for faster kinetics. The oxygenconcentration should be controlled to avoid complete oxidation of thechar as:

C+O->CO₂ ΔH°=−393 kJ/mol  [5]

The first three reactions are endothermic, while the fourth isexothermic. The energy for the first three reactions can come fromchanneling internal heat generated from the fourth reaction or fromexternal sources, e.g., combustion of coal or natural gas, orelectricity during off-peak hours. In principle, the heat generated fromcreating 2 moles of CO via the fourth reaction can be used to power thefirst three reactions. The following reactions are also relevant forthis discussion:

H₂O+CO->H₂+CO₂ ΔH°=−41 kJ/mol  [6]

CH₄+½ O₂->CO₂+2H₂O ΔH°=−802 kJ/mol  [7]

CH₄+½ O₂->CO+2 H₂ ΔH°=−35 kJ/mol  [8]

CH₄+H₂O->CO+3 H₂ ΔH°=207 kJ/mol  [9]

Equation 1 in particular deserves notice for allowing vast stores ofmethane to be converted to hydrogen. Present methane reformation on coalproduces synthesis gas contaminated with sulfur, since the coaltypically contains a few percent by weight of sulfur. The sulfur in thesynthesis gas causes catalyst poisoning, and it is removed from thesynthesis gas before introducing the latter into a catalyst bed. Thisrepresents extra cost and complexity, particularly for small scalemodular plants. According to embodiments of the invention, the BMF charis actually cleaner than the incoming methane, leading to high puritysynthesis gas.

Equation 1a evinces that carbon atoms from methane decomposition add afresh layer to the BMF char surface. Any impurities in the methanefeedstock, such as sulfur-based impurities, will tend to be buried inunderlying high surface area char surface and eventually accumulate inthe ash. The methane may be derived from a number of sources, includingstranded gas and wet gas. This process is thus inherently resistant toimpurities, but still able to produce high purity synthesis gas. Theability to add oxygen or water ensures that the BMF char surface remainsactive, as long as the CO removal rate is greater than the carbondeposition rate from the methane reaction. The BMF char can thus beconsidered to act as a sacrificial catalyst in that it is not consumedin the overall reaction, but does react sacrificially duringintermediate stages.

The oxygen in the above reactions may economically be obtained from anair stream, it may also be obtained from a gas that comprises oxygenwith a different concentration, such as gas containing pure oxygen, orgas obtained front the decomposition of an oxygen carrying species suchas N₂O, H₂O, H₂O₂ or alcohols. The carbon dioxide may be obtained fromgas recycled from the bio fractionation process 420, the separationprocess 480, the syngas conversion to fuels process 460, or externalsource 431.

Any one combination of CH₄, H₂O, CO₂ and O₂ may be also be used to reactwith the BMF char to create synthesis gas reaction products, includingoxygenates such as aldehydes, ethers, esters, alcohols, andcarboxylates. The following lists the possible combinations in relationto reactions involving BMF char and a methane stream:

C+CH₄+O₂

C+CH₄+H₂O

C+CH₄+CO₂

C+CH₄+H₂O+O₂

C+CH₄+CO₂+O₂

C+CH₄+H₂O+CO₂

C+CH₄+O₂+H₂O+CO₂

In these cases, proper channeling of reactants is required to minimizeformation of carbon dioxide as given, in equations 6 and 7.

In one embodiment, the preferred temperature range for the BMF charreactions listed above is in the range of 800° C. to 1100° C., and mostpreferably 850° C. to 1050° C. The synthesis gas produced is used inprocess 55 for a wide variety of purposes. It may be converted intooxygenates and hydrocarbons via a number of different catalyticprocesses, including methanol synthesis processes. Fischer-Tropschchemistry, and synthesis gas fermentation. The synthesis gas may also bedirectly combusted. The hydrogen may be separated from the carbonmonoxide and used as feedstock for the ammonia synthesis process or as areactant in fuel cells. The BMF char may also be combined at any stageafter its formation with typical chars.

Adjustment of H2/CO Ratio in BMF Char Reactions

The reactions above may occur concurrently or sequentially in one orseveral reactors. It is understood that best practice entails carefulmonitoring of reactant concentrations and of reaction products to adjustthe output ratios of hydrogen to carbon monoxide. It should be notedthat there is no catalyst involved as typical processes that rely onwater gas shift catalysts. The BMF char is a sacrificial agent for theultimate production of hydrocarbons, in essence representing a moreefficient use of the biomass. Temperature, pressure and space velocitywill affect the results and distribution of synthesis gas products. Thehydrogen to carbon monoxide ratio can be varied depending on the natureof feedstock and quantity of material. Indeed, a stream can beengineered to produce a stream comprising of 100% hydrogen, or one of100% carbon monoxide, or any compositional mixture of the two. Thus afeedstock comprised exclusively of methane can provide a source of purehydrogen, while a feedstock comprised of oxygen can provide a source ofpure carbon monoxide. The two sources can then be mixed in any ratio. AH₂/CO 2:1 ratio is preferable for the methanol production while dimethylether requires a 1:1 ratio.

Another method of adjusting ratio is to utilize a wider range ofreactants. A wide range of H₂/CO ratios can be obtained from usingdifferent combinations of reactants, chosen from methane, oxygen, waterand carbon dioxide. The actual ratios will depend on the chemicalequilibrium of all species, which is determined by temperature,pressure, and concentration of reactants and products. As mentionedabove, energy for some of the BMF char reactions can be derived eitherfrom external or internal sources. External sources refer to energysupplied in the form of recycled waste heat, or waste heat orelectricity coming from outside the system described by the presentinvention. Internal sources refer to energy channeled from theexothermic reactions, such as shown in equations [4] and [5].

Thermal management via internal energy sources may be achieved with theappropriate combination of reactants to render the synthesis gasformation close to energy neutral.

FIG. 6 shows a block diagram of an embodiment of the present inventionin which synthesis gas generation arises out of cellulose decompositionand biochar conversion, and subsequent feeding of converted synthesisgas to the fuel product line. An optional methane feed is provided forgreater control of the synthesis gas ratio.

Systems Using Present Invention

Processes 410, 420, and 470 in FIGS. 4 and 5 can be carried out on asmall enough scale to minimize transport costs of biomass to the reactorsite. An embodiment of a system 1400 that executes basic processes ofthe present invention in one machine running a conveyor line as shown inFIG. 14. This system 1400 comprises hoppers 1410 for biomassdispensation, dewatering stations 1420, biofractioning stations 1430,synthesis gas stations 1440, cooling stations 1450, and a station 1460for removing biochar from machine onto another conveyor belt. Thissystem can be placed on semi-tractor trailer track for transport toother locations. An illustration of a larger processing facility 1500 isshown in FIG. 15. One individual trailer houses equipment for anindividual process such as biomass pretreatment, biofractionating, fuelconversion including separation and blending, and biochar processingincluding synthesis gas conversion. A command center is also shown.

ILLUSTRATIVE EXAMPLE

The following example describes an embodiment of the invention. 100 g ofwood chips are brought to a pyrolysis process in nominally dry form.Further drying removes 10 g of water. 90 g of wood chips represents 45 gof carbon input to the process. 80 g of methanol are brought in asco-feed, representing 21 g carbon co-fed into the process. The waterremoval takes 30 KJ of external energy, which represents approximately2.1 g CO₂ (0.6 g carbon) emissions from a natural gas thermal process.Other steps in the pyrolysis and conversion processes consume externalenergy that amounts to 15 g CO₂ (4 g carbon) emissions. The pyrolysisand conversion processes produce 34 g of fuel total (31 g carbon), and34 g of sequesterable biochar in separate and uncontaminated form. Anadditional 3.7 g CO₂ (1 g carbon), which is produced within thebiofractonation process, is vented out. Following the procedure in FIG.11, the 34 g of sequesterable carbon is greater than the non-biomasscarbon inputs (21 g+0.6 g+4 g), and consequently the fuel produced fromthis process is negative carbon. Per the earlier definition of variableN, the fuel can be labeled N110.

In terms of the carbon dioxide balance, the wood chips removed 165 g ofCO₂ from the atmosphere via photosynthesis and 113.7 g of CO₂ werereleased back into the atmosphere from burning fuel in a vehicle. Energyfor drying wood, process energy and process venting contributed to 20.8g CO₂ emissions to the atmosphere. Energy inputs from other sources arenot included. A net of 30.5 g of CO₂ was removed from the atmosphere.

Although the invention is described above in terms of various exemplaryembodiments and implementations, it should be understood that thevarious features, aspects and functionality described in one or more ofthe individual embodiments are not limited in their applicability to theparticular embodiment with which they are described, but instead can beapplied, alone or in various combinations, to one or more of the otherembodiments of the invention, whether or not such embodiments aredescribed and whether or not such features are presented as being a partof a described embodiment. Thus, the breadth and scope of the presentinvention should not be limited by any of the above-described exemplaryembodiments.

Terms and phrases used in this document, and variations thereof, unlessotherwise expressly stated, should be construed as open ended as opposedto limiting. As examples of the foregoing: the term “including” shouldbe read as meaning “including, without limitation” or the like; the term“example” is used to provide exemplary instances of the item indiscussion, not an exhaustive or limiting list thereof; the terms “a” or“an” should be read as meaning “at least one,” “one or more” or thelike; and adjectives such as “conventional,” “traditional,” “normal,”“standard,” “known” and terms of similar meaning should not be construedas limiting the item described to a given time period or to an itemavailable as of a given time, but instead should be read to encompassconventional, traditional, normal, or standard technologies that may beavailable or known now or at any time in the future. Likewise, wherethis document refers to technologies that would be apparent or known toone of ordinary skill in the art, such technologies encompass thoseapparent or known to the skilled artisan now or at any time in thefuture.

The presence of broadening words and phrases such as “one or more,” “atleast,” “but not limited to” or other like phrases in some instancesshall not be read to mean that the narrower case is intended or requiredin instances where such broadening phrases may be absent. Additionally,the various embodiments set forth herein are described in terms ofexemplary block diagrams, flow charts and other illustrations. As willbecome apparent to one of ordinary skill in the art after reading thisdocument, the illustrated embodiments and their various alternatives canbe implemented without confinement to the illustrated examples. Theseillustrations and their accompanying description should not be construedas mandating a particular architecture or configuration.

1. A method for making negative carbon fuel from a carbon-containinginput, comprising: subjecting a carbon-containing input to a thermalprocess to obtain a volatile gas stream and an inert carbonaceous solid,wherein the volatile gas stream and the inert carbonaceous solid areformed as separate components in the process and wherein a portion ofthe carbon from the carbon-containing input is contained in the inertcarbonaceous solid; and converting the volatile gas stream to one ormore of combustible fuels, refinery feedstock or chemicals.
 2. A methodfor making negative carbon fuel from a carbon-containing input,comprising: subjecting a carbon-containing input to a thermal processcomprising one or more processing steps to obtain an inert carbonaceoussolid and one or more combustible fuels, refinery feedstock orchemicals, wherein the one or more combustible fuels, refinery feedstockor chemicals and the inert carbonaceous solid are formed as separatecomponents in the process, and wherein a portion of the carbon from thecarbon containing input is contained in the inert carbonaceous solid. 3.The method of claim 1 or 2, wherein the carbon-containing inputcomprises biomass.
 4. The method of claim 1 or 2, wherein the inertcarbonaceous solid is suitable for storage in the ground.
 5. The methodof claim 1 or 2, wherein the inert carbonaceous solid is chemicallyinert and is not attacked by acids, bases, biological activity or othermechanisms commonly found underground.
 6. The method of claim 1 or 2,wherein the inert carbonaceous solid is suitable for use as a soilenhancer.
 7. The method of claim 1 or 2, wherein the inert carbonaceoussolid is suitable for use as a soil fertilizer.
 8. The method of claim 1or 2, wherein the inert carbonaceous solid is suitable for use asactivated charcoal.
 9. The method of claim 1 or 2, further comprising:sequestering the carbon of the inert carbonaceous solid by introducingthe inert carbonaceous solid into the ground.
 10. The method of claim 1or 2, further comprising: sequestering the carbon of the inertcarbonaceous solid by converting the carbonaceous solid intoanthracite-style carbon aggregations.
 11. The method of claim 1 or 2,further comprising: sequestering the carbon of the inert carbonaceoussolid by addition to soil containing compost material.
 12. The method ofclaim 1 or 2, wherein the inert carbonaceous solid is used for carbonoffsets.
 13. The method of claim 1 or 2, wherein the inert carbonaceoussolid is used for carbon credits.
 14. The method of claim 1 or 2,wherein at least some of the inert carbonaceous solid is reacted withoxygen, carbon dioxide, methane or steam to generate synthesis gas, andwherein the synthesis gas is converted to combustible fuels, refinerystock or chemicals.
 15. The method of claim 1, wherein the volatile gasstream is recovered from the thermal process in a product stream that isseparate from that of the inert carbonaceous solid.
 16. The method ofclaim 1 or 2, wherein the one or more combustible fuels, refineryfeedstock or chemicals is recovered from the thermal process in aproduct stream that is free of the inert carbonaceous solid.
 17. Themethod of claim 1 or 2, wherein the one or more combustible fuels,refinery feedstock or chemicals obtained from the thermal process has acarbon negativity of at least 100 (N100).
 18. The method of claim 1 or2, wherein the one or more combustible fuels, refinery feedstock orchemicals obtained from the thermal process has a carbon negativity ofat least 105 (N105).
 19. The method of claim 1 or 2, wherein the thermalprocess comprises subjecting biomass to ramps of temperatures underpressure.